Anthracene compound.



UNITED STATE s PAirENT oFFio PAUL THOMASCHEWSKI, OF VOHWINKEL, NEAR ELIBERFELD, GERMANY. ASSIGNOR TO FARBENFABRIKEN VORM. FRIEDR. BAYER & 00., OF ELBERIEELIDv GERLIANY,

A CORPORATION OF GERMANY.

ANTHRACENE COMPOUND.

No Drawing.

To all whom it may concern."

Be it known that I, PAUL THoMAscHEwsKI, doctor of philosophy, chemist; citizen of the German Empire, residing at Vohwinkel, near Elberfeld, Germany, have invented new and useful Improvements in Anthracene Compounds, of which the following is a specification. a

This invention relates to the production of a new anthracene derivative being chemically the leuco-compound of LS-dibenzoyldiaminoanthraquinone. It is obtained by treatin 1.8-dibenzoyldiaminoanthraquinone with hydrosulfite and caustic soda lye.

20 parts of a 10 per cent. paste of 1.8-dibenzoyldiaminoanthraquinone, 20 parts of caustic soda lye (34 B.) and 2 parts of sodium hydrosulfite (free from water) are dissolved in 50, parts of water heated to 30 C. A red-brown solution results from.

which the leuco compound is precipitated by the addition of common salt. It is-in the shape of its sodium salt a brown crystalline powder turning yellow by the action of air, which is the color of the 1.8-dibenzoyldiaminoanthraquinone. It is soluble in water with a'red-brown color,yellow flakes of 1.8- dibenzoyldiaminoanthraquinone being pre- 7 Specification of Letters Patent. Application filed June 29, 1909. Serial No. 505,034.

Patented Nov. 2,1909.

cipitated after some time soluble in concentrated sulfuric acid with a green color quickly turning orange-yellow. Its alkaline solution dyes the textile fiber orange-yellow shades.

I claim:

T he herein described new anthracene derivative which is the leuco compound of 1.8-dibenzoyldianiinoanthraquinone obtainable by treating 1.8-dibenzoyldiaminoanthraquinone with hydrosulfite and caustic alkali, which product is in the shape of its sodium salt a brown crystalline powder turning yellow by the action of air. soluble in water with a red-brown color; soluble in concentrated sulfuric acid with a green color quickly turning orange-yellow; furnishing 1.8-dibenzoyldianiinoanthraquinonc by treat ment with oxidizing agents; and dyeing the textile fiber orange-yellow shades, substantially as described.

In testimony whereof Ihave hereunto set my hand in the presence of two subscribing witnesses.

' PAUL THOMASCBEWSKI. [1 5.] Witnesses:

O'r'ro Komo, VVILLY KLEIN. 

